Method of making embossing dies



Feb. 18, 1930. G. R. MEYERCORD ETAL 1,747,311

METHOD 0F MAKING EMBOSSING DIES File@ March 25, 1929 2 Sheets-Sheet 1 Feb. 18, 1930. G. R. MEYl-:RcoRD El'u. 1,747,311

' METHOD OF.MAKING EMBOSSING DIES Filed March 25, 1929 2 Sheets-Sheet 2 illustrating successive steps in the comple- Patented Feb. 18, 1930 UNITED STATES PATEN'r OFFICE GEORGE R. MEYERCORD, OF CHICAGO, ILLINOIS, AND CHARLES B. NORRIS, OF GRAND RAPIDS, MICHIGAN, ASSIGNORS TO HASKELITE MANUFACTURING CORPORATION,

A CORPORATION 0F NEW YORK Application mea March 25, 1929. serial No. 349,889.

` 15 reference may be had to the following detailed description taken in connection with the accompanying drawings, wherein:

Fi re 1 is a section through a copper shell whic is to form the working face of the female. die; Figs. 2 and 3 are sectional views tion of the rudimentary female die; Fig. 4 is a plan view of the female die block positioned upon a temporary supporting plate; Fig. 5 -is a section on line 5 5 of Fig. 4; Fig. 6 is a plan view of the completed female die and its holder; Fig. 7 is a section taken approximately on line 7-7 of Fig. 6; Fig. 8 is a perspective view of the cast iron case for the male die; Fig. 9 `is a view partly in section and .partly fin elevation, showing theparts illustrated in Figs. 4 and 8 assembled preparatory to the casting of the male die;

vand Fig. 10 is a section through the complet- 35 ed male die.

. In embossing a panel by pressing itbetween complementary dies, that die which lengages the sideof the panel that is tobe the front or face of the latter when embossed must 'be` sharp and distinct and be of comparatively hard mate-rial.- The wood ispressed into the cavities-of this,-die,w;which is thezfemale,-zby the other die acting von the back .ofl the panel.

placed in the tray, the edges This other die,the male, While'it should `be areasonable- -it in `the complementary die, may. "1f befmade oa Soft matenal. .e :.f i Y- f. have; feund :that electro.-deposi,tedA copperfpossesses f a fsullcient.. degree of har-dV ness to adaptitforuse as the femaleQdie face...

Therefarewe begnfthefmanufacturetithe,.-

dies by making a female die in the form of a comparatively thin copper shell l. This shell is composed of copper electro-deposited. to a thickness of about a sixteenth of an inch. The shell 1 may be produced in any suitable way. Ordinarily, a Wax impression will be made of an original wood carving; a copper shell in the form of a male die will be electrodeposited upon the wax im ression; this first copper shell, covered light y with Wax, dusted with graphite, may serve as a foundation upon which to electro-deposit a female co per shell. If only one set of working dies 1s required, this female shell may be used in theA production of the working dies. However, where a plurality of similar sets of working dies are required, vwax impressions may be made from the second copper shell and shells for the Working female dies may b e electro-deposited on these wax impressions. l

Having the copper shell 1, it is placed face `down in a shallow cast iron tray 2. First however, the inside of the tray and the face of the shell are painted with a paint composed of powdered graphite, zinc oxide, commercial sodium silicate, and water. Proportions that have been found to be satisfactory are as follows: raphite sixty-five grams; zinc oxide sixtyve ams; commercial sodium silicate 3c. c. an water 170 c. c. The graphite andthe zinc oxide are mixed dry andthe mixture of sodium silicate and Water is then addedl thereto. Afterfthe shell-has been are covered= smoothly with a putty. We have found that a putty made of one part of commercial sodium silicate` and nine parts .of water, together with sufficient*` asbestos cement to give;- thel` proper consistency willi serve the, purpose satisfactorily... The` shell is-k covered toy a depth of abouty one-half Linch with' a linx, as indicated# at 3v in Fig.` 2.3 a flux `we. havesuccessfully employed: a` mixe ture" of.- five parts of zincv chloride *and* one 2 part ofzcupreouschloride. Suitable weights,-

material composed of galvanized one-eighth inch steel wire of about ive-eighths inch mesh will ordinarily serve the desired purpose which is to reinforce the casting to be made in the manner now to be described.

A tank of molten white metal is prepared. A suitable white metal is that commercially known as Sampson metal, which is an alloy of zinc, copper and aluminum. The tank may be made out of steel plate. The white metal is kept at a temperature of about 900o F. The tray and its contents, and the piece of wire mesh, are placed in the moltenlmetal and, when the tray becomes heated to the temperature of the .white metal, some of the latter is ladled into the tray and the latter is then removed from the tank and permitted to cool. The weights are removed andthe back of the shell is brushed lightly with a Wire brush to remove any small particles of flux which might adhere to it. The fiux is carefully skimmed from the surface of the metal in the tray and then the piece of wire mesh is lifted out of the tank and dropped into the tray. The wire mesh is pressed down until it' is in Contact with or at least close to the copper shell. The white metal hardens first around its edges. As soon as the edges become hard, they are clamped to the tray by means of suitable clamps, such as shown at 5 in Fig. 3. The clamping of the edges of the casting prevents the casting from warping as it cools. After the casting has become cool, it is removed from the tray, the copper shell adhering to it. At this point the female die has reached a stage'in which it consists of a more or less rough casting 6 of white metal faced on one side with the copper shell 1 and having embedded therein a reinforcing Wire mesh 7.

The back of the die block is machined until it is flat, and one edfre is also machined. Holes 8 are bored through the block at each end of the copper element, the ends of the copper element forming diameters for these holes. vThe block is then placed, face up, upon a plate 9 provided with stops 10 against which the finished edge of the block rests, as shown in Fig. 4. The plate is provided with dowel pins 11 that extend up through theholes 8 in the die block.

The male die is made in single operation by using the female die as a part of a mold cavity into which is poured molten metal. As a. foundation for the male die we employoa cast iron tray-like case 14 the top of which is depressed about a quarter of an inch or three-eighths of an inch throughout almost its entire area, leaving a comparatively narrowledge or rim 15 along the edges. From the bottom of the depression rise numerous projections 16. The flange or rim is cut away at one side and the edge of the case in this zone is beveled as indicatedat 17 to produce a gate into which molten metal may be poured.

ber of C-shaped stops of the kind indicatedV at 19 in Fig. 9 are placed in position to engage the plate 9 and the back of the cast iron case. Wedges are then driven between the female die block and the case so as to spread the block and the case apart as far as the stops will permit. The crack produced in what may be termed the mold by spreading the halves apart is stopped up by means of putty, as indicated at 20 in Fig. 9. A putty for this purpose that has been found to be satisfactory is one made of cylinder oil mixed with ground asbestos, that has been stored in a warm place until it has aged. Of course no putty is placed along the line of the gate. Molten zinc heated to a temperature of about 900o F. is then poured through the gate until the mold cavity is filled. The female die block vand its supporting plate are then removed,

iron case to which is permanently united ablock of zinc 21 having its face in the form of a male die.

Afterthe female die block has been used as a pattern for the casting of the male die, the three edges that remain unfinished are machined, the ends being cut olf' along the lines of the edges of the copper shell, cutting the holes 11 in half. The block is then set into a closely-fitting case 25, as shown in Figs. 6 and 7, having vdowel pins 26 positioned to engage in the half holes in the female die block. Consequently, when a panel is placed between t-he two die blocks and the latter are brou ht together, the pins 26 cause the two die aces to register accurately. The case into which it is fitted prevents the bodyof the female die block from spreadin heavy pressures; the tray 14 serving t is same purpose with respect to the male die block.

`While We have illustrated and described with particularity the details of the preferred method and of preferred forms of devices, we

do not wish to limit `ourselves to suchdeta-ils ;y

but intend to cover all'methods and forms of construction coming within the definitions of our invention constituting the appended claims.

1. The method of producing a die for emthe adherence of molten white metal, laying the shell, face clown, in the tray, eoverin the shell with a flux,l heating the tray an its contents to the temperature of molten white metal, and then pouring molten white metal under lao into thetray and removing the flux that rises to the top of the white metal.

2. The method of producing a die for embossing plywood in imitation of carving, which consists in producing athin copper shell having on one side the desired die face, painting said face and the inside of a cast iron tray with a material that will prevent the adherence of molten white metal, laying the shell, face down, in the tray, covering the shell with a flux, heating the tray and its contents to the temperature of molten white metal, pouring molten white metal into the tray, and pressing down into the White metal a reinforcing member heated to about the same temperature as the white metal.

3. The method of producing a die for embossing plywood in imitation of carving, .Which consists in producing a copper shell having on one side the desired die face, casting a thick layer of white metal upon the back of said shell, and clamping the casting in the vicinity of its edges as soon as it has hardened at the edges, thereby to prevent warping of the casting while the center hardens.

4. The method of producing a die for embossing plywood in imitation of carving,-

which consists in producing a copper shell having on one side the desired die face, placing the shell face down in a cast iron tray,

heating the tray and its contents, pouring molten white metal into the tray, and pressing a heated piece of heavy wire mesh into the molten lnetal to form a reinforcement for the latter upon hardening.

6. The method of producing a die for embossing plywood in imitation of carving1 which consists in producing a copper shell having on one side the desired die face, laying the shell face down in a cast iron tray, covering the shell with a flux, holding the tray ina body of molten white metal Without permitting the molten metal to flow into the tray, and, when the tray and its contents have been heated to the temperature of the molten metal, lifting out the tray and pouring some of the molten white metal into the same.

7. The method of producing a die for embossing plywood in imitation of carving, which consists in producing a" copper shell having on one side the desired die face, laying the shell face down in a cast iron tray, covering the shell with a flux, holding a piece of heavy wire mesh and also the tray in a cation.

GEORGE R'. MEYERCORD. CHARLES B. NORRIS.

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